Anatomy of an Ebola outbreak

A confirmed case of the deadly Ebola virus in eastern Uganda three weeks ago has been quickly contained, leading health experts in the country to believe the virus has not spread.

“According to the present report, it seems the virus didn’t pass to anybody,” said Issa Makumbi, head of epidemiology and surveillance in the Ministry of Health, said on 25 May.

A 12-year-old girl died on 6 May in Luwero district, just 75km from the country's populous capital Kampala. Health officials said at the time that more cases were expected but to date, it remains the only confirmed case of the Sudan Ebola strain, which has a 50-60 percent fatality rate.

Ebola is a deadly disease characterized by fever, diarrhoea, severe blood loss and intense fatigue. It is transmitted through direct contact with the bodily fluids of infected persons.

Makumbi said the speedy response of the National Task Force “has paid dividends” in the number of lives saved.

Uganda’s first outbreak in the northern Gulu district in 2000 killed 224 people, with 425 infected. It was the first time the Sudan strain had appeared in more than two decades, and remains the largest documented Ebola epidemic so far.

The second outbreak in 2007 that killed 37 people in the western Bundibugyo district took months for health officials to identify, according to Salim Wakabi, an Ebola researcher working with the Makerere University Walter Reed Project (MUWRP).

“It took about three months from the first dead up to the time the ministry said, ‘You know what, there is an Ebola outbreak’,” said Wakabi.

Makumbi said the delay was due to it being a completely new strain – now coined the Bundibugyo strain. It presented less obviously than its Sudanese counterpart, and was easily mistaken for malaria.

This third outbreak of the contagious and incurable fever has now passed the halfway mark to 42 days, when officials will be able to declare the outbreak over, Makumbi said.

Who does what

Outline of roles:

National Task Force

- led by government through the Ministry of Health

- coordinates national, district, sub-county, village health teams as well as local NGOs and outside partners;

Head of epidemiology and surveillance, Ministry of Health

- early detection and reporting of outbreaks

- heads coordination alongside Director General of Health Services;

WHO - provides technical support;

UNICEF - provides mass communication, public information;

Centers for Disease Control (CDC)

- laboratory support;

AFENET (the African Field Epidemiology Network)

- technical support including outbreak response, laboratory capacity and surveillance

Uganda Red Cross Society

- assist with surveillance, community mobilization/information;

USAID - logistical supplies;

Tullow Oil - recently donated 75 million shillings (US$32600) to help with social sensitization and mobilization.

(Source: Head of epidemiology and surveillance, Ministry of Health)

He attributed the quick response to heightened awareness and ongoing surveillance by health officials, as well as the state-of-the-art Uganda Virus Research Institute (UVRI) laboratory in Entebbe that was able to quickly diagnose the disease.

Julius Lutwama, the head of laboratory activities at UVRI, has battled all three outbreaks in Uganda, and says this was the first time he had not had to go out into the field.

“More and more people are getting used to the infection, coming in and being brave enough to go and investigate the cases,” he said.

Working on a vaccine

The lab is one of only a handful on the continent able to test for Ebola – and Uganda is the first African country working towards developing a vaccine.

The team at the helm, MUWRP, is not one of the primary response units, but behind a long-term effort to try to establish the root and a possible cure. It is also trying to establish the factors that allow some infected by Ebola to survive, as well as researching the long-term health effects of being infected by the virus.

“The turn-out was overwhelming when we started the vaccine trial because people appreciate and know the problem is with us,” Wakabi said.

Makumbi said Ebola was an “emerging pandemic” in Uganda, which needed long-term commitment by coordinating partners to be able to trace the rarely found source. “It’s becoming like cholera, every now and then we get it,” he said.

While primates have been the most common source of infection for humans, their high mortality rate suggests they are not the natural reservoir for the virus.

According to the World Health Organization, the reservoir “seems to reside in the rain-forests on the African continent and in the Western Pacific” but is still unknown, despite extensive studies.

Wakabi said the vaccine being developed in Uganda, if successful, would not be ready before five years. Last year, an experimental vaccine developed in the United States was found to cure the virus, but only if it was administered within 30 minutes of being infected.

While this was seen to be unhelpful in curbing epidemics, it could potentially save the lives of health workers infected at work.